-LRB- CNN -RRB- -- The father of George Zimmerman , the man accused of shooting and killing and unarmed black teen , says the teen threatened to kill Zimmerman and beat him so badly that it forced Zimmerman to shoot Trayvon Martin .

`` Trayvon Martin said something to the effect of you 're going to die now or you 're going to die tonight , something to that effect , '' Robert Zimmerman told Orlando news station WOFL . `` He continued to beat George . At some point , George pulled his pistol . Did what he did . ''

In the interview Robert Zimmerman , his face obscured because he says he fears for his safety , vehemently defended the shooting that has caused outrage throughout the nation , moved President Obama to call it a tragedy and prompted a federal investigation .

Robert Zimmerman told the news station that Martin confronted his son first and pummeled his son continually .

`` He was punched in the nose . His nose was broken , '' Robert Zimmerman said . `` He was knocked to the concrete . Trayvon Martin got on top of him and just started beating him . In the face . In his nose , hitting his head on the concrete . ''

Robert Zimmerman was not there the night of the shooting and did not say during the interview how he knew the details of the altercation .

The elder Zimmerman 's account was disputed by Martin 's family attorney and several other legal experts .

A surveillance video taken the night of the incident at police headquarters shows Zimmerman , his hands cuffed , exiting a patrol car .

The video , first broadcast Wednesday by ABCNews.com , shows an officer looking at the back of Zimmerman 's head . The video did not provide a close-up of Zimmerman 's head but some say it shows Zimmerman did not have significant injuries to his face .

`` The injuries that made it sound as though he really should have been on a stretcher are not apparent in this tape at all , '' said Marcia Clark , the former prosecutor in the O.J. Simpson trial . `` He moves freely . He moves fluidly , not like someone who has just been through a beating in anyway shape or form , someone 's whose head has been pounded on the pavement as hard as described , someone who 's nose was broken and bleeding . That tells you a great deal . ''

Sybrina Fulton , Martin 's mother , said the video is another strong piece of evidence proving her son was killed unjustly .

`` I believe that this video is the icing on the cake , '' she said . `` This is not the first part of the evidence that they have had . They have had the 911 tapes and they have also have witnesses . This is in addition to what the Sanford Police Department has always had . There is no problem with this case and he needs to be arrested . ''

The 17-year-old was shot to death February 26 by George Zimmerman , a neighborhood watch volunteer , as Martin was walking back to his father 's fiancee 's house in Sanford , Florida . He was wearing a hoodie and carrying Skittles candy and a can of iced tea he had purchased from a nearby convenience store .

Zimmerman says he killed Martin in self-defense after the teen attacked him in the gated community . Zimmerman has not been arrested and authorities have said said he has not been charged because there are no grounds to disprove his story of what happened .

The shooting has hit a nerve in the nation , sparked a debate about racial profiling and ignited protests and calls for Zimmerman 's arrest .

Robert Zimmerman said his son is having a hard time dealing with the criticism .

`` I never foresaw so much hate coming from the president , the Congressional Black Caucus , the NAACP . Every organization imaginable is trying to get notoriety or profit from this in some way , '' Robert Zimmerman told WOFL . `` But there 's so much hate that I have never been involved in hate and George has n't . It 's really unbelievable . ''

Robert Zimmerman said her son is not racist and race had nothing to do with incident .

`` He would do anything to help anybody at any time . He 's color blind when it comes to any race , '' Robert Zimmerman said .

Tracy Martin , Martin 's father , said Wednesday that the 911 tape shows Zimmerman was profiling his son .

In a recording of Zimmerman 's call to police , some people have said they hear what sounds like a possible racial slur . CNN enhanced the sound of the 911 call , and several members of CNN 's editorial staff repeatedly reviewed the tape but could reach no consensus on whether Zimmerman used a slur .

Angela Corey , the special prosecutor assigned to investigate the case , said Tuesday that investigators would look into the allegations that Zimmerman used a racial slur .

Martin , who lived in Miami , was visiting Sanford after receiving a 10-day suspension from school , a family spokesman has said . An empty plastic bag found in his book bag was determined to contain marijuana residue .

Crump , Martin 's parents ' attorney , said information regarding the suspension was irrelevant and amounts to a smear campaign against the youth .

Florida law allows the use of deadly force anywhere a person feels a reasonable fear of death or serious injury . It has been cited in a number of justifiable homicide cases in Florida .

But as more and more information surfaces , the picture of what happened becomes more complicated .

Despite the twists and turns in the case Fulton , Martin 's mother , says she still has faith in authorities investigating her son 's case .

`` I feel confident that they 're going to do a thorough investigation , '' Fulton said . `` We 're trying to be patient , even though it 's been over a month . We 're trying to be patient , and we 're trying to press on for justice . ''

CNN 's Umaro Djau , Deirdre Walsh , Ed Payne and Tracy Sabo contributed to this report .

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Video shows Zimmerman at police station

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`` He continued to beat George , '' father tells news station

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Martin family and some legal experts say videos shows Zimmerman was not severly beaten